Vacuum boiling pan



y 4, .1. J. NEUMAN 2,289,801

VACUUM BOILING PAN Filed April 1i, 19 39 3 Sheets-$heet 1 J] JQCOZ IAZWM J. J. NEUMAN VACUUM BOILING PAN July 14, 1942."

3 Sheets-Sheet 5 Filed April 1], 1939 g 5 5 I g JacoZ J a 4 W PatentedJuly 14, 1942 VACUUMI BOILING PAN Jacob J. Neuman, South Salem, N. Y.,assignor to United States Patent Development and Royalty Company, SouthSalem, N. Y.

Application April 11, v1939*, Serial N0. 267,355

9 Claims.

This invention relates to new and useful improvements in vacuum boilingpans and the like employed to increase the density of solutions orliquors or to recover the solute by evaporation of the solution orliquid.

One of the primary objects of the present invention is to increase therate of boiling of the liquor in apparatus of this character by means ofa movable heating element disposed in' the vacuum boiling pan, whichheating element serves not only to heat but simultaneously to agitatethe material in the vacuum pans and thereby provide uniform heating ofthe material undergoing treatment.

Another object of the present invention is to employ an internalcombustion engine or the like power means for driving the moving heatingelement in the vacuum pan and to transfer the heat from the drivingmeans to the heating element by a heat transfer system whereby a highthermal efiiciency is obtained.

Still another object is to provide a circulating system for a heatingmedium in fluid communication with a movable heating element disposed ina vacuum pan and to utilize the heat generated by the driving means forthe movable heating element to heat the heating medium.

A further object of the invention is to provide a movable heatingelement in a vacuum pan to heat and simultaneously agitate the materialundergoing treatment in combination with an internal combustion enginefor driving the heating element and to transfer the heat from the engineto the heating element by means of a circulating system for a heatingmedium, said system including means for storing the heating mediumduring periods when it is not needed for processing in the vacuum pan.

With the foregoing and other objects in View, the invention will be morefully described hereinafter, and will be more particularly pointed outin the claims appended hereto.

Inthe drawings, wherein like symbols refer to like or correspondingparts throughout the several views,

Figure 1 is a side elevation of the improved vacuum pan, itsinstallation and connections, all as constructed in accordance with thepresent invention, parts being broken away and parts being shown insection.

Figure 2 is an enlarged vertical central section ing the connectionsthereto partly broken away and partly in section, and V Figure 4 is avertical section of the lower portion of the vacuum pan showing thehollow shaft support and rotating mechanism.

In the drawings, referring first to Figures 1 and 2, the improved vacuumpan is composed of a casing made up of two or more identical sections Isecured together in any appropriate manner. Such column or casing iscrowned by the cap 3. The lower endof the column is supported upon thebase 4, which is preferably of inverted conical form, leading to anoutlet through which the treated material may be dumped or evacu ated.The sections I together with the cap 3 and base 4 form the completeshell of the pan. Sepa-- rators 5 are shown within the pan near theupper and lower ends of the pan for supporting baffle plates 5 Aseparator 6 and baffle plate B are shown centrally within the pan.Obviously more separators and baffie plates might be used in the case ofa pan employing more than two sections I; or the baffle plates might beomitted for pans of certain types; or the baliie plates might be rerarranged as desired.

the flights to the shaft.

taken through the vacuum pan and hollow rotat- The upper cap 3 isdesigned for pipe connection to the vacuum creating condenser pipe linei. It also has incorporated in it vertical mem-. bers 8 to support theupper bearing 9 of the shaft H]. The shaft I0 is hollow and constitutesa moving or rotating heater element. A gland packing ll is provided to'assure a tight joint where the shaft l0 passes through the upperportion of the pan cap 3. The new type gland with spring-retainedpacking, as hereinafter described, may be used at this point ifnecessary instead of the conventional gland packing.

The base 4 is provided with a gate Zl suitable and 4, is connected todrive the hollow shaft [0- and is attached near the lower end of theshaft. The shaft II] is provided with a step thrust bearing I4 ofsuitable type to support the shaft I6 vertically and to hold the bevelgear I3 in positive alignment with the drive pinion I3 preventinglateral displacement.

As shown more particularly in Figure 2, the heater element of the pan isin the form of a substantially V-shaped hollow helix or screw attachedby suitable means to the shaft I6. This helix or screw, while apparentlycontinuous from an external viewpoint, is divided into a number ofsections to which the fluid heating medium is separately supplied.

In Figure 2 two such sections are shown. The upper sectionalized flightI5 of the heater element receives its heating medium through an openingI6 in the shaft III. The hollow shaft I!) itself provides a passage forthe fluid downwardly to and through opening I6 and into the upper end ofthe hollow flight section I5.

As shown in Figure 3, the hollow space or passage Il within shaft Ireceives the heating fluid from a pipe I8 connected at the upper end ofthe passage Reverting to Figure 2, an opening IS in the shaft near thelower end of the top flight section provides a path for the heatingmedium to re-enter the hollow shaft I0 after circulating through thesection I5. This lower section of the shaft has an internaluninterrupted space 20 with which the opening I9 directly communicates,such passage 20 being for the purpose of carrying off the heating mediumand its condensate after passing through the hollow flight sections. Thepassages I! and 20 are both within the hollow shaft l0 and they areseparated by a plug 2| which is set just below opening |6 therebypreventing the passage of the heating medium received in the upper shaftpassage I! from flowing directly down into the lower passage 26 of thepipe section and being evacuated by that passage 26. The plug 2| alsoacts as a heat insulated support for the inner pipe 22. This inner pipeis of smaller diameter than the internal diameter of the shaft I6 thusforming with the shaft II] the annular passage IT. The inner pipe 22provides a means of introducing fluids to the bottom sectionalizedflight 23.

As shown in Figure 3, the inner pipe 22 receives its fluid supply froman inlet connection 51 at the top thereof. Reverting to Figure 2, thelower end of pipe 22 is turned as indicated at 24 and passed through thepipe I!) to cause communication with the first convolution of the lowerhollow helix 23 whereby to cause the fluid or heating medium tocirculate downwardly through the bottom helix down toward a dischargeopening 25 in the shaft I0 which allows the fluid or its condensate topass out from the bottom helix 23 into the lower passage 26 of hollowshaft I0, thereby to be evacuated.

It will be noted that the openings I9 and 25, both being dischargeopenings, each communicate with the passage 20 in the lower part ofshaft I0. This passage or common chamber 26 within the hollow shaftconstitutes an unimpeded path to the outlet fitting 33 at the lower endof the hollow shaft as shown in Figures 1 and 4.

Referring more particularly to Figure 1, in which the vacuum pan isshown as coupled in an operating system, 3| represents a multiplecylinder internal combustion engine, the drive shaft of which isrepresented at 32. As shown in Figme 4 this drive shaft drives the bevelgear I3 75 which through bevel pinion |3 drives shaft II) of therotating heater element.

The engine shaft 32, at the opposite end of the internal combustionengine, drives a generator 35 for providing power at a constant voltagesuitable for use on equipment within reasonable distances of powertransmission and distribution. The generator is equipped with suitableautomatic voltage control 36 which regulates the field current of saidgenerator 35 in suitable relationship with the speed of the internalcombustion engine to give constant voltage within the reasonableoperating range of speeds of said engine 3|.

The exhaust gases from the internal combustion engine 3| are dischargedtherefrom through outlet or exhaust pipe 31 into the muffler andoxidizing chamber 38. In the muiiler the exhaust gases are mixed with anexcess of air and a supply of volatile oil vapor, thereby insuringcomplete combustion of all incompletely burned gases. From the muflierand oxidizing chamber 38 the completely burned gases are led through theair cooler 39, where, by means of counterflow arrangement of tubescarrying fresh and exhaust air, the latter gives up practically all ofits heat to the former, providing heated fresh air for the internalcombustion engine air intake and the blower by means of the warm airpipe 4|, M The blower 40 also receives warm air through the pipes 4| and4| and blows this warm air into the muffler 38 through the pipeconnection 4|. An oil jet 42 projects into pipe 4|, or in other wordsinto the air line from the blower 40 to the chamber 38. The jet 42 is incommunication with a suitable source of oil supply. The air passing jet42 picks up the oil and volatilizes the same in suflicient quantities toinsure that the burning thereof within the muffier 38 shall becontinuous.

Both mufiler 38 and air cooler 39 are equipped with drainage pipes 44which permit any condensate formed to be led away to a suitable waterpipe or drainage system. The fluid which circulates in the hollow flightsections of the vacuum pan and which is evacuated through the bottomchamber 2|] of the hollow shaft I0 is received in the outlet fitting 33,as shown more particularly in Figure 4, and circulated by means of thepipe connection 28 to the casing which houses the bevel gears I3 and I3This fluid or circulating medium leaves the bevel gear reduction driveunit I3, I3 after absorbing heat while passing through its water jacketis pumped into the high pressure line by the pump 45, a pipe 45connecting the inlet of pump 45 with the outlet side of the bevel gearcasing I3 Storage tanks are indicated at 6| and 62, such storage tankscontaining make-up fluid or circulating medium. The bottoms of the tworeserved tanks 6| and 62 are connected with the inlet of pump 45 bymeans of apipe line 66. Valves 63 and 64 control the outlet of fluidrespectively from tanks 6| and 62. The pipe 35 is connected with asource of additional make-up medium supply and a valve 65 controls theinlet of such additional or new make-up material. Pump 45 pumps fluidfrom the gear casing I3 together with any needed make-up medium oradditional quantity necessary from the reserve storage tanks 6|, 62depending on the adjustment of valve 46 interposed in the pipe line 66.The relative amounts of reserve and new make-up medium introduced aredetermined by the setting of make-up medium valve 65 and reserve supplyvalves 63 and 64 for the tanks 6| and 62 respectively.

This fluid or circulating medium may be water, mercury or any othersuitable volatile liquid or evaporated gas thereof which could be usedto transfer heat from one heat exchange apparatus to another to permitthe high thermal efiiciencies necessary to the economical operation ofthe set-up.

n the outlet side of pump 45 are pipe connections 48 and 48 havingvalves 41 and 52 therein. Part of the medium from pump 45, according tothe adjustment of valve 41, circulates through the cooling jacket aroundthe cylinders of the internal combustion engine 3|, thereby gainingconsiderable heat while at the same time cooling the engine to a safeoperating temperature. After circulating through the cooling jacket ofthe engine this fluid passes out into pipe 49 and on through valve 50 topipe I 8 which leads into the upper end of shaft ID by means of fittingThe circulation of this fluid or circulating medium through the worm orscrew of the vacuum pan has already been described.

The circulating medium from the engine cooling jacket may also be partlyled away upwardly through bleeder valve 58 for other uses or throughvalve 63 into tank SI for reservation until again needed.

The pump 45 also circulates medium from the cooling casing 13' of thespeed reduction drive unit i3, l3 together with the needed make-upmedium, according to the adjustment of valve 52 to and through thecooling jacket of the mufiler or oxidizing chamber 38 and on out throughthe line 53. A part of this circulating medium may be led out of thesystem according to the adjustment of the bleeder valve 54, or passed byvalve 59 into reserve tank 52. The remaining medium will pass throughvalve '55 into the pipe line 55. This line is connected to the interiorchamber or pipe 22 of the hollow shaft through the end connection 51, asshown to best advantage in Figure 4. The flow of the medium from thispoint downwardly through the lower flight section has already beendescribed. This medium after being evacuated from the lower flightsection is again circulated to the gear reduction casing I3".

It is apparent that there may be alternate methods of circulating themedium according to the relative temperature rises and heat availablebut the principle of using all thermal energy from the exhaust gases andspeed reduction gears will hold by any arrangement of piping. Also, thesystem, to insure complete combustion of exhaust gas from the en ine,will not be changed in principle by arranging the air intake ahead ofthe combustion and oxidizing chamber.

In operation the substance to be processed is brought in at the top ofthe vacuum pan l and after being treated is discharged through the base4 of the pan either in a continuous opera tion or at intermittentperiods. This substance is subjected in the pan to the heat treatment ofthe continuously rotated worm or screw, this worm itself progressingspirally through the fluid substance being treated and thus causing allexternal areas upon the flights to come in contact with large volumes ofthe substance being treatedrand at the same time causing movement in thesubstance being treated so as to bring all parts of that fluid or liquidsubstance into physical contact with the external heating surfaces ofthe worm or flights.

The worm is driven by the internal combustion engine 3| which alsodrives generator and which provides the means for storing up heat in theheating medium which is used in the vacuum pan.

The water jacket of the internal combustion engine furnishes hot wateror steam through pipe 49 to connection 18 and to the chamber ll of thehollow shaft 10.

After this hot water, steam o other heating medium circulates throughthe upper hollow flight section I5 it is returned through the passage 25in the hollow shaft [0 down to thegear casing I3 In the gear casing theheat spent in the hollow flight section begins to build up again. Thisreheated medium from casing I3?) is circulated by pump through pipeconnection 48 back to the water jacket of the engine, although part ofit may be diverted through pipe 43 to the water jacket of the mufiier38. The hot water, steam or other heated medium from the jacket of themuffler 38 is circulated by pipe 53 to the connection 51 and thence bypipe 22 to and through the bottom hollow flight section 23 of the vacuumpan, eventually escaping therefrom into passage 25 of the hollow shaft15 and thence to the gear casing I3 in which the spent heating mediumundergoes an initial reheating, the same being finally heated either inthe engine water jacket or in the muffler jacket,

The heating medium not needed is stored in the reservoirs or tanks GIand 62 from which it is withdrawn as occasion arises through pipe 56 andcirculated back into the system by the pump 45.

Fresh air is heated in the cooler 39 by the products of combustionpassing through the same from the mufller 38, and this heated fresh airis delivered by pipes 4i and 4| to the intake of the internal combustionengine and also by pipes 4i and 4| to the inlet air pipe 41 of themuffler into which oil vapor is introduced by the jet or nozzle 42 forthe purpose of effectually burning all the products of combustion.

By means of the valves and the heating medium may be turned only intothe bottom coil 23 initially if that is desired, and later as the massin the vacuum pan envelops the upper flight section I5, the valve 55 maybe opened to allow that upper section l5 to become heated. Also theflight sections may be heated at different temperatures. Thus in thebeginning of the operation, the upper half of the vacuum pan isordinarily empty so that the top flight would be left unheated toexclude the possibility of small masses of liquor and the solidstherefrom sticking to the otherwise hot surface and becoming scorched,discolored or decomposed. In the case of evaporating milk or liquors oflow density, the use of all heater flights would be desirable from theoutset. As the evaporation progressed and the substance in the panretired downwardly below the upper flight sections the heat might beturned off from those sections to avoid accidental decomposition of thesubstance incident to boiling fluid being splashed against the hotsurfaces of upper exposed flight sections. Thus the sectionalized flightarrangement with the individual control for separately heating thesections provides a flexible vacuum pan operating upon a new method ofoperation and in which heat may be delivered to any part of the pan andany portion of the substance therein for the purpose of individuallytreating that substance in the manner as best suits the needs of thenature of that substance to the end that processing of the substance maybe carried out in a minimum space of time Without subjecting thesubstance to deterioration, decomposition, burning, discoloration or anyother defects to which existing apparatus and methods subject thematerial.

In Figures 1 and 3 the pipe nipples l3 and 51 are shown as coupled toflexible pipe sections I8 and 51 to allow for variations in fittingconnections and to permit alignment of the parts and also to permit freeplay of the packing.

It is obvious that various changes and modifications may be made in thedetails of construction and design of the above specifically describedembodiment of this invention without departing from the spirit thereof,such changes and modifications being restricted only by the scope of thefollowing claims.

What is claimed is:

1. An apparatus of the kind described comprising an internal combustionengine, a vacuum pan, a movable heater element in said vacuum pan,driving gear connections between said engine and heating element, acasing about said driving gear connections for receiving fluid, anexhaust mufiier for the internal combustion engine having a jacket incommunication with said casing and with a source of reserve supply ofheating medium, a pump between said casing and jacket, and means forcirculating the heating medium from said jacket to the heater element inthe pan.

2. In apparatus of the kind described, an internal combustion engine, anexhaust mufiler therefor having a jacket, an air cooler for receivingthe products of combustion from said muffler and having a counterflowfresh air passage therethrough in communication with the air intake ofthe engine and with the exhaust gas space of said muffler, a waterjacket for the engine, a vacuum pan, a movable heater element in saidvacuum pan, gear connections from said engine for driving said movableheater element, a casing for said drive connections having a space forheating medium, connections between said casing and the jacket of themuffler, connections also between the water jacket and the jacket ofsaid mufiler, connections for conveying off from the jacket of themuffler the heating medium to said heater element, means for storingexcess quantities of said heating medium and for connecting the excesssupply in a closed cycle with the jacket of said mufiler, means for alsosupplying from the water jacket of the engine heating medium to saidmovable heater element of the pan, a reserve supply coupled to said lastmeans and in a closed cycle with the water jacket of the engine andhaving connection to the jacket of the muffler, and means for evacuatingthe spent heating medium from the heater element of the pan into saidcasing.

3. Apparatus of the class described comprising in combination, a vacuumpan, a rotatable hollow screw element in said vacuum pan, a circulatingsystem for a fluid medium to heat said screw element, and an internalcombustion engine for rotating said hollow screw element and for heatingthe fluid medium in said circulating system.

4. Apparatus of the class described comprising in combination, a vacuumpan, a hollow rotatable screw element in said vacuum pan, a

circulating system for a fluid medium to heat said screw element, aninternal combustion engine for heating the fluid medium in saidcirculating system and for rotating said screw element, and means insaid system for storing the heating medium for periods when it is notneeded for processing purposes in said vacuum pan.

5. Apparatus of the class described comprising in combination, a vacuumpan, a rotatable hollow screw element vertically mounted in said pan,acirculating system for a fluid medium having inlet connection to theupper portion of said hollow screw element and outlet connection fromthe bottom of said hollow screw element, and an internal combustionengine for heating the fluid medium in said circulating system and forrotating said screw element.

6. Apparatus of the class described comprising in combination, a vacuumpan, a rotatable hollow screw element in said pan divided longitudinallyinto a plurality of separate hollow flight sections, a circulatingsystem for a fluid medium in communication with said separate sections,and an internal combustion engine for heating the fluid medium in saidsystem and for rotating said screw element.

7. Apparatus of the class described comprising in combination, a vacuumpan, a hollow shaft rotatably mounted in said vacuum pan and having aplurality of hollow helical sections to form a screw element, each ofsaid helical sections having a fluid inlet connection adjacent one endthereof and a fluid outlet connection adjacent the opposite end, thefluid outlet connection of each of said sections communicating with theinterior of said hollow shaft, a fluid outlet connection at one end ofsaid hollow shaft, a circuit for a fluid medium in communication withthe inlet connections to said helical sections and with the outletconnection from said hollow shaft, an internal combustion engine forheating the fluid medium in said circuit, and means operativelyconnecting said engine with said hollow shaft to rotate the latter.

8. Apparatus of the class described comprising in combination, a vacuumpan for concentrating the crystallizable liquids, a hollow rotatablescrew element in said pan, an internal combustion engine, a coolingjacket for said engine, a circuit for a fluid medium in communicationwith said jacket and with said hollow rotatable screw element, means forcirculating the fluid medium through said circuit whereby the heat takenup by said fluid medium in flowing through said cooling jacket istransferred to said screw element to heat the material being processedin said vacuum pan, and means operatively connecting said engine to saidscrew element to rotate the latter.

9. Apparatus of the class described comprising in combination, a vacuumpan, a rotatable hollow screw element in said vacuum pan, a circulatingsystem for a fluid medium to heat said screw element, an internalcombustion engine for rotating said hollow screw element, means forheating the fluid medium in said circulatin system, and auxiliary meansfor supplying additional heat energy to the fluid medium in saidcirculating system.

JACOB J. NEUMAN.

